Heat insulating tape



lApril 22, 1941. w. F. AsTLr-:Y y12,239,281

' HEAT INsULATI-n TAPE L Filed oci. 19, 1959 2 sheets-sheet 1 r l "f' f2 l April 22,' A1941.

w. F. AS1-LEY 2,239,231

HEAT INSULATING TAPE Filed oct. 19, 1959 z sheets-sheet 2 Patented Apr., 22, 1941 ururEDv STATES PATENT- OFFICE I.

2,239,281 HEAT INSULATING TAPE WiilianrF. Astley, Cicero, 1li.,

Asbestos t Rubber Company,

- corporation of Illinois assignor to Unionl (Jhicago, lli., a

Application October 19, 1939, ScriallNo. 300,104 5 claims. (ci. 13s-42o) The present inventionrelates to heat insulating tape and methods of manufacture of tape of the character having an external woven sheath and a filling comprising a plurality of large, loose, sort insulating members or rovings.

The ,methods of manufacture of heat insulating tapes`of this type ofthe prior art included the separate weavingfrof the tape, and thereafter the tape was filled according to various methods, but this mode of manufacture was subject to the disadvantage that it required considerable manual labor, special equipment for iilling the tape, etc.

'One of .the objects of the present invention is the provision of .an improved tape and method of manufacturlirilg the -same which includes the weaving of t e sheath about .the fillers.

When the fillers of the prior -art are drawn into lthe sheath, there is a tendency for the filler to get `out of place, and naturally there is a tende" ency for elongation of the ller and flattening. According to lthe present method, in which the sheath is simultaneously woven with the placing of the filler, the fillers cannot. get out of place, and the ller units may be maintained in large, loose, and soft-condition, without any tendency toward' flattening or elongation because .they are not subject to theA same kind of tension as is necessary in the, devices of the prior art.

Another object of: the invention is the provision of an improved structure /of insulatingtape, in which one side of the sheath, which is intended to be on the outside when the tape is Wrapped spirally about a pipe, is purposely made longer,l as evidenced by a wavy or puckered condition of the sheath, so as to compensate for the increased peripheral length required in the fabric which, is disposed ata greater radius from the center of the pipe, in order .to prevent the tendency of the tape to atten out .definite posmc wtinin the sheath.

the iiller by virtueof the increased tension in the outer wall of the sheath. y

fibers which may Another object of the invention is the provision of an improved insulating tape of the type having a sheath and an insulating ller in which the i increasing the Atensile pressing. against the filler,y and tending to ilatten it. 1

Another object of the invention i'sthe provision f an improved tape ofthe class described, havin'g a plurality of longitudinally extending relatively hard ropes on one side ofthe sheath for engagement with the pipe upon which the tape is wrapped, in order to form a plurality of spirally extending chambers of dead air between the tape and the pipe, .to increase the insulation value of the tape.

Other objects and advantages of the invention will be apparent from 'of the une z-z or Fig. 1;

Fig. Bis another sectional view, taken on the planeo! the line l-t of Fig. 2;

Fig. 4 is a sectional view through a pipe upon which the tape have been wrapped;

Fig. 5 is a diagrammatic view in perspective,

showing the structure' of tnetape end ns nner; l

Fig. 6 is a view similar to Fig'. 5, showing another modication.

Referring to the drawings, f Figs. 1 and 2" illustratethe structure of the tape which .is made according to ,my present method of weaving the sheath about the filler.

The iiiler comprises a plurality of large,-loose,

vsoft rovings Wto I3, each of which has a thread aboutit for the purpose of strength and maintaining the roving as a unit.

Il, spirally wrapped The rovings comprise units made of asbestos include a small percentage'ofA cotton, and the'thread'is` likewise of asbestos fibers with a small percentage of cotton, The size and shape of the rovings at the center of the tape vary from the center toward the outer edges, but the four center rovings I0 to 'I3 may be of substantially the same size.

'The edges of the tape preferably include a pair of small rovings I5 and lia, and the rovings may edges of .the sheath are provided with relatively hard filler membersfor the purpose of eiecting a bridge aroumwhich the sheath may extend., to .prevent the two flatfsides of the sheath from be pre-shaped to provide a tape of predetermined cross-section. f

The sheath, indicated 4in its entirety by the numeral I6, comprises a tubular member woven the following description l and the accompanying drawings, in which similar 'characters of reference indicate similar partsl out of asbestos threads, which may include a small percentage of cotton to increase` the tensile strength, and in some conditions may include fine copper or brass wires. 'Ihe sheath may be woven of the warp threads I'I, and the weft threads i8, and any type of weave may be used.

such as a plain'weave, a granite weave, a diag. y onal twill or a herringbone twill.

f use of reeds of suchl a coarse structure that the The sheath is preferably provided with certain' warp threads i9, which extend from the outer wall 20 of the sheath to/the lower wall 2| of the sheath, for the purpose oi locking certain of the rovings in predetermined position and preventing the shifting of the rovings within the sheath.

The lowr or inner wall 2| oi the sheath is preferably provided with a plurality of longitudinally extending ropes 22, 23, 24, and 25, which are woven in and secured by predetermined weft threads 26 at regularly spaced intervals.

The ropes 22 to 25 are twisted quite tightly and made of twisted asbestos threads, and two of the ropes 22 and 25 are preferably located adjacentl the outer 4edges of the sheath. The spaces 21, 2l, f

and 29 between the ropes 22 to 25 form spirally extending/ dead air spaces when the tape is wrapped on the pipe, substantially as shown in Fig. 4.

One of the most important features of the invention is the provision of a definite crimp, or whaty may bev described' as wrinkles, or a wavy formation a't 3l (Fig. 5) in the outersurface of the sheath for the purpose of giving the outer wall 20 of the sheath an additional length which it requires when it is wrapped on the pipe because the outerwall is disposed at a greater distance from the center of the pipe, where the circumferenceis greater.`

This crimp gives the so that the outer wall does not tend .to -ilatten the filler members Il to lla, as would be the case when the inner and outer walls are of the same length. 'The crimp' or additional length in the outer wall is provided by feeding an additional length of warp fibers to the middle of the outer wall of the sheath, such as, for example, twenty percent'. more of length of warp. 'Thismay be 'done by providing a feeding drum for these particular warp strands, which feeding drum is of greater diameter at the middle, where these warp strands pass about( it.

In other embodiments, twenty-two totwentyfour percent of' crimp has been provided, and in one embodiment sixteen percent of crimp'has 'been provided.

.Referring to Fig. 6, this embodiment of the inventionjis provided'with 'three ropes 3l, '22, and 33,A at each edge of the tape, the rope 3| being disposed-above `and\below the tapes 32. Il.

' the weaving of the sheath simultaneously aboutlouter wall suilicient length This provides s hara nner er definite tinck'- I ness at the edge of the tape, which acts as a bridge for the outer wall 2l and the inner wall.y 2| of the sheathy The outerl and inner walls may, in

a way, be tensiozied across the bridging ropes 3| to 33 from one side to the other, without tending to flatten the inner fillers Il 'to ll.

In addition to providing the warp fibers of the outer wallsof lthe sheath with additional warp length, the method preferably includes a feeding device, such as a toothed Lwheel, which engages that portion of the sheath =and draws it out of the machine step by step at a greater speed than the\s peed at vwhich -the main of the tapeemerges.

This provides a denite 'crimp 3l adenite fillers may be passed between them, and the llers Il to Il are protected by being passed through the metal tubes which guide them and protect them inside the reeds.

'I'he structure can be woven either as a tape or a blanket, and tapes are customarily made in the sizes of 2% by 11'; by, and 2 by ,is inches. A blanket of the same structure has been woven in the dimension of 19% by V4 inches.

It should be understood that the external wall 2l of the sheath, extending over to and'around the abutting edges at 31 and Il, may be covered with a layer of waterproofing material, such as an initially plastic asphalt composition. This makes the external surface vof the tape not only waterproof. but air-tight, and prevents convection. currents of air from passing through the insulation of the tape on account of the air-tight outer wall, when the tape-has been wrapped on the pipe. y Y

My methodcomprises the feeding of the large, loose, and soft rovings side by side through protective tubes passing through a coarse reedand the fillers. The warp threads at the center, outside wall of the sheath are fed in greater length than the warp threads of any other part of the sheath, so as to give the outer. wall greater `length, and the outer wall of the sheath is ldrawn from the loom by a feeding device which forms wave or crimp in this outer wall of the sheath. i The finished tape may go directly from the weaving 'machine to pass over rollers which `dip into the waterproofing compound and apply the wuterproong compound to the outside and edge only of the tape, the Jrollers being of complementary shape to the tape, and the tape may thereafter pass into an electric heater for drying the waterproofing compound and evaporating the solvent from its. A Thereafter the i tape may -be immediately lwrapped in rolls in condition to be placed on-the market. y A

'It will thus be observed that I have invented an improved method of making insulating tape of the type having a sheath and a 1111er of asbestos Vrovings or fibers and an improved structure of theI tape. having better insulating qualiles.

The improved structure at the edge of the filler is adapted to prevent thinning of the edge and permit the bridging of the fillers by the inner and outerywalls of the sheath. The additional length provided in the outer wall of the sheath prevents the tendency toward the flattening of the filler by the tension which would be placed in the-outer wall dus to its greater distance from 'or an excess in v the cuter'wall of the sheatn'so as to prevent 75 as it emerges from lthe weavinggmachine effects the center of the Pipe.

' The simultaneous placing of the fillers side by side and weaving of the sheath about them effects c considerable saving in the cost of the tape, and

eliminates much manual labor and additional operations in the manufacture of the tape. h

The complete process of waterproofing 'the tape further economies and increases the heat insulating value of the tape.

While I have illustrated a preferred embodiment 'of my inventiommany modications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself oi' all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. A heat insulating tape comprising a plurality of large, loose, soit rovings located side by side to form a filler. and a sheath woven about said rovings, said sheath being of substantially tubular form, said sheath including warp and -weft strands and having an outer and inner wall, and the warp strands of the outer wall of the sheath being of greater length than those of the inner wall for the purpose of ,providing a sheath having an outer wall of sufllcient length to wrap about a pipe without 4compressing the illler.

2. A sheath for heat insulating tape, comprising a wov 4n tubular member consisting of warp threads and weft threads adapted to receive an insulating filling, said tubular member being oval in shape and formed with an outer face having its warp threads of predetermined greater length than the other warp threadsof said sheath whereby the sheath may be applied to a curved surface and the increased length of the warp that part oi the sheath to prevent compression of the filler, due to tension oi the outer face, said sheath beingvprovided with a plurality of longitudinally extending cords located on the other face o! said sheath and adapted to engage the curved surface to which the sheath is applied.

4. A sheath for heat insulating tape, comprising a woven tubular member consisting of warp threads and weft threads adapted to receive an insulating filling, said tubular member being oval in 'shape and formed with an outer face having its warp threads of predetermined greater length than the other warp threads of said sheath whereby the sheath may be applied to a curved surface and the increased length of the warp threads in the outer face will provide sutiicient length for that part of thesheath to prevent compression of the filler, due to tension of the outer face, and a ller comprising a plurality of large, loose, soft rovings of insulating material inside said sheath, said rovings being disposed side by threads in the outer face will provide suilicient length for that part of the sheath to prevent compression of the iiller, due to tension of the outer face.

3. A sheath for heat insulatingtape, comprising a woven tubular member consisting of warp threads and weft threads adapted to receive an insulating filling, said tubular member being oval in shape and formed with an outer face -havingy its warp threads of predetermined greater length than the other warp threads of said sheath whereby the sheath may be applied to a curved surface and the increased length of the warp threads in the outer face will provide suilicient length for side and effecting a substantial filling of said sheath.

5. A sheath for heat insulating tape, compris- Iing a woven tubular member consisting of warp threads and weft threads adapted to receive an insulating filling, said tubular member being oval in shape and formed with an outer face having its warp threads of predetermined greater length than the other warp threads of said sheath l whereby the sheath may be applied to a curved surface and the increased length of the warp threads in the outer face will provide suiiicient length for that part of the. sheath to prevent compression of the ller, due td tension of the outer face, and a ller comprising a plurality of large, loose, soft rovings ofinsulating material inside said sheath, said rovings being disposed side by side, and a. hard rope assembly at each edge of said iilling inside said sheath, said hard rope assembly being adapted to serve as spacers for spacing the `opposite walls of said sheath and bridging the lling with a minimum amount oi! compression on the rx vings.

WILLIAM F.- ASTLEY. 

